The 4-amino-1,2,2a,3,4,5-hexahydrobenz[cd]indoles are useful intermediates to a number of valuable compounds. For example, Bach and Kornfeld, U.S. Pat. No. 4,110,339, disclose that 4-(di-n-propyl)amino-1,3,4,5-tetrahydrobenz[cd]indole, useful as a prolactin inhibitor and in the treatment of Parkinsonism, is readily prepared from 1-benzoyl-4-amino-1,2,2a,3,4,5hexahydrobenz[cd]indole. Additionally, Flaugh, U.S. Pat. No. 4,576,959, discloses a family of 6-substituted-4-dialkylamino-1,3,4,5-tetrahydrobenz[cd]indoles, useful as antidepressive agents and as anxiolytic agents (as disclosed by Leander, U.S. Pat. No. 4,745,126), some of which were prepared from substituted 4-amino-1,2,2a,3,4,5-hexahydrobenz[cd]indoles. In both of these inventions, the desired intermediates were prepared via circuitous routes from the Kornfeld-Woodward ketone, Kornfeld et al. , J. Am. Chem. Soc. , 78, 3087 (1956): ##STR1##
Furthermore, Glaser et al., EPO 148,440, disclose another series of 6-substituted-4-amino-1,3,4,5-tetrahydrobenz[cd]indoles. Flaugh, et al., J. Med. Chem., 31, p.p. 1746-1753 (1988) teach a method of preparing the 6-methoxy compound of Glaser et al. which utilizes 4-amino-6-methoxy-1,2,2a,3,4,5-hexahydrobenz[cd]indole.
This invention provides intermediates and processes for efficiently deriving 4-amino-1,2,2a,3,4,5hexahydrobenz[cd]indoles from the Kornfeld-Woodward ketone. A preferred embodiment of the invention provides intermediates and processes for a stereospecific synthesis of 4-amino-1,2,2a,3,4,5hexahydrobenz[cd]indoles.